(a) Field of the Invention
This invention relates in general to electronic displays. More specifically, it relates to Plasma and AC/DC Electroluminescent (EL) displays and provides brightness control for such Plasma and AC/DC Electroluminescent displays.
(b) Description of the Prior Art
With the increased use of portable personal computers, Plasma and Electroluminescent displays are becoming more popular. Many software applications such as, for example, word processing, spreadsheet, and computer aided design, use half/full intensity attributes of a video output to highlight important data or convey information to the user. Intensity control of a conventional cathode ray tube (CRT) is well known. There are now standard circuit arrangements for controlling the intensity (brightness) of a CRT.
However, Plasma and Electroluminescent displays "off the shelf" that are integrated into personal computers, and the like, do not have intensity control. When such displays are utilized for the video output of a software package that calls for brightness control to convey some information to the user, that information is not conveyed. The user will not, for example, see "highlighted" data that would be apparent if the data were displayed on a conventional CRT.